Justin Bieber Detained by Customs at Los Angeles Airport

Update

By Sheila Cosgrove Baylis

UPDATED 04/24/2014 at 09:55 PM EDT • Originally published 04/24/2014 at 08:05 PM EDT

Justin Bieber returned from Asia to find that re-entering the U.S. would not be easy.

The singer was detained at Los Angeles International Airport by U.S. Customs officials Thursday.

A source tells PEOPLE that Bieber was detained "for routine secondary questioning" but was not being kept out of the United States.

Bieber, 20, had reportedly been held for almost four hours inside Tom Bradley International Terminal after flying in from Tokyo while his entourage waited for him, but he was eventually released, according to E! News.

The pop star's DUI arrest and assault charges have prompted a petition to repeal the Canadian singer's green card.

The White House Monday said they would not comment on the petition, which has almost than 274,000 signatures.

"Sorry to disappoint, but we won't be commenting on this one," reads the statement, which then went on to discuss larger immigration issues.

Immigration experts have said that Bieber is unlikely to be deported.